root / slirp / slirp.c @ d64477af
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#include "slirp.h" |
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|
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/* host address */
|
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struct in_addr our_addr;
|
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/* host dns address */
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struct in_addr dns_addr;
|
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/* host loopback address */
|
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struct in_addr loopback_addr;
|
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|
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/* address for slirp virtual addresses */
|
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struct in_addr special_addr;
|
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|
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const uint8_t special_ethaddr[6] = { |
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0x52, 0x54, 0x00, 0x12, 0x35, 0x00 |
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}; |
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|
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uint8_t client_ethaddr[6];
|
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|
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int do_slowtimo;
|
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int link_up;
|
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struct timeval tt;
|
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FILE *lfd; |
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|
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/* XXX: suppress those select globals */
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fd_set *global_readfds, *global_writefds, *global_xfds; |
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|
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#ifdef _WIN32
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|
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static int get_dns_addr(struct in_addr *pdns_addr) |
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{ |
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/* XXX: add it */
|
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return -1; |
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} |
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|
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#else
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|
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static int get_dns_addr(struct in_addr *pdns_addr) |
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{ |
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char buff[512]; |
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char buff2[256]; |
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FILE *f; |
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int found = 0; |
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struct in_addr tmp_addr;
|
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|
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f = fopen("/etc/resolv.conf", "r"); |
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if (!f)
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return -1; |
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|
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lprint("IP address of your DNS(s): ");
|
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while (fgets(buff, 512, f) != NULL) { |
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if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) { |
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if (!inet_aton(buff2, &tmp_addr))
|
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continue;
|
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if (tmp_addr.s_addr == loopback_addr.s_addr)
|
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tmp_addr = our_addr; |
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/* If it's the first one, set it to dns_addr */
|
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if (!found)
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*pdns_addr = tmp_addr; |
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else
|
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lprint(", ");
|
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if (++found > 3) { |
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lprint("(more)");
|
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break;
|
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} else
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lprint("%s", inet_ntoa(tmp_addr));
|
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} |
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} |
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if (!found)
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return -1; |
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return 0; |
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} |
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|
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#endif
|
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|
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void slirp_init(void) |
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{ |
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debug_init("/tmp/slirp.log", DEBUG_DEFAULT);
|
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|
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link_up = 1;
|
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|
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if_init(); |
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ip_init(); |
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|
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/* Initialise mbufs *after* setting the MTU */
|
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m_init(); |
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|
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/* set default addresses */
|
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getouraddr(); |
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inet_aton("127.0.0.1", &loopback_addr);
|
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|
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if (get_dns_addr(&dns_addr) < 0) { |
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fprintf(stderr, "Could not get DNS address\n");
|
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exit(1);
|
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} |
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|
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inet_aton(CTL_SPECIAL, &special_addr); |
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} |
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#define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
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#define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
|
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#define UPD_NFDS(x) if (nfds < (x)) nfds = (x) |
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|
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/*
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* curtime kept to an accuracy of 1ms
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*/
|
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static void updtime(void) |
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{ |
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gettimeofday(&tt, 0);
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curtime = (u_int)tt.tv_sec * (u_int)1000;
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curtime += (u_int)tt.tv_usec / (u_int)1000;
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|
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if ((tt.tv_usec % 1000) >= 500) |
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curtime++; |
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} |
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|
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void slirp_select_fill(int *pnfds, |
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fd_set *readfds, fd_set *writefds, fd_set *xfds) |
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{ |
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struct socket *so, *so_next;
|
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struct timeval timeout;
|
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int nfds;
|
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int tmp_time;
|
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|
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/* fail safe */
|
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global_readfds = NULL;
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global_writefds = NULL;
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global_xfds = NULL;
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nfds = *pnfds; |
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/*
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* First, TCP sockets
|
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*/
|
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do_slowtimo = 0;
|
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if (link_up) {
|
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/*
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* *_slowtimo needs calling if there are IP fragments
|
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* in the fragment queue, or there are TCP connections active
|
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*/
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do_slowtimo = ((tcb.so_next != &tcb) || |
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((struct ipasfrag *)&ipq != (struct ipasfrag *)ipq.next)); |
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|
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for (so = tcb.so_next; so != &tcb; so = so_next) {
|
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so_next = so->so_next; |
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|
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/*
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* See if we need a tcp_fasttimo
|
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*/
|
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if (time_fasttimo == 0 && so->so_tcpcb->t_flags & TF_DELACK) |
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time_fasttimo = curtime; /* Flag when we want a fasttimo */
|
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|
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/*
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* NOFDREF can include still connecting to local-host,
|
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* newly socreated() sockets etc. Don't want to select these.
|
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*/
|
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if (so->so_state & SS_NOFDREF || so->s == -1) |
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continue;
|
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|
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/*
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* Set for reading sockets which are accepting
|
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*/
|
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if (so->so_state & SS_FACCEPTCONN) {
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FD_SET(so->s, readfds); |
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UPD_NFDS(so->s); |
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continue;
|
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} |
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|
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/*
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* Set for writing sockets which are connecting
|
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*/
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if (so->so_state & SS_ISFCONNECTING) {
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FD_SET(so->s, writefds); |
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UPD_NFDS(so->s); |
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continue;
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} |
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|
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/*
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* Set for writing if we are connected, can send more, and
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* we have something to send
|
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*/
|
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if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) {
|
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FD_SET(so->s, writefds); |
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UPD_NFDS(so->s); |
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} |
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|
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/*
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* Set for reading (and urgent data) if we are connected, can
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* receive more, and we have room for it XXX /2 ?
|
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*/
|
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if (CONN_CANFRCV(so) && (so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) { |
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FD_SET(so->s, readfds); |
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FD_SET(so->s, xfds); |
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UPD_NFDS(so->s); |
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} |
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} |
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|
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/*
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* UDP sockets
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*/
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for (so = udb.so_next; so != &udb; so = so_next) {
|
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so_next = so->so_next; |
202 |
|
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/*
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* See if it's timed out
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*/
|
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if (so->so_expire) {
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if (so->so_expire <= curtime) {
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udp_detach(so); |
209 |
continue;
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} else
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do_slowtimo = 1; /* Let socket expire */ |
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} |
213 |
|
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/*
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* When UDP packets are received from over the
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* link, they're sendto()'d straight away, so
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* no need for setting for writing
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* Limit the number of packets queued by this session
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* to 4. Note that even though we try and limit this
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* to 4 packets, the session could have more queued
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* if the packets needed to be fragmented
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* (XXX <= 4 ?)
|
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*/
|
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if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) { |
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FD_SET(so->s, readfds); |
226 |
UPD_NFDS(so->s); |
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} |
228 |
} |
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} |
230 |
|
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/*
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* Setup timeout to use minimum CPU usage, especially when idle
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*/
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|
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/*
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* First, see the timeout needed by *timo
|
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*/
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timeout.tv_sec = 0;
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timeout.tv_usec = -1;
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/*
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* If a slowtimo is needed, set timeout to 500ms from the last
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* slow timeout. If a fast timeout is needed, set timeout within
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* 200ms of when it was requested.
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*/
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if (do_slowtimo) {
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/* XXX + 10000 because some select()'s aren't that accurate */
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timeout.tv_usec = ((500 - (curtime - last_slowtimo)) * 1000) + 10000; |
248 |
if (timeout.tv_usec < 0) |
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timeout.tv_usec = 0;
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else if (timeout.tv_usec > 510000) |
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timeout.tv_usec = 510000;
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/* Can only fasttimo if we also slowtimo */
|
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if (time_fasttimo) {
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tmp_time = (200 - (curtime - time_fasttimo)) * 1000; |
256 |
if (tmp_time < 0) |
257 |
tmp_time = 0;
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|
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/* Choose the smallest of the 2 */
|
260 |
if (tmp_time < timeout.tv_usec)
|
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timeout.tv_usec = (u_int)tmp_time; |
262 |
} |
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} |
264 |
*pnfds = nfds; |
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} |
266 |
|
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void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds)
|
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{ |
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struct socket *so, *so_next;
|
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int ret;
|
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|
272 |
global_readfds = readfds; |
273 |
global_writefds = writefds; |
274 |
global_xfds = xfds; |
275 |
|
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/* Update time */
|
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updtime(); |
278 |
|
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/*
|
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* See if anything has timed out
|
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*/
|
282 |
if (link_up) {
|
283 |
if (time_fasttimo && ((curtime - time_fasttimo) >= 199)) { |
284 |
tcp_fasttimo(); |
285 |
time_fasttimo = 0;
|
286 |
} |
287 |
if (do_slowtimo && ((curtime - last_slowtimo) >= 499)) { |
288 |
ip_slowtimo(); |
289 |
tcp_slowtimo(); |
290 |
last_slowtimo = curtime; |
291 |
} |
292 |
} |
293 |
|
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/*
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* Check sockets
|
296 |
*/
|
297 |
if (link_up) {
|
298 |
/*
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* Check TCP sockets
|
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*/
|
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for (so = tcb.so_next; so != &tcb; so = so_next) {
|
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so_next = so->so_next; |
303 |
|
304 |
/*
|
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* FD_ISSET is meaningless on these sockets
|
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* (and they can crash the program)
|
307 |
*/
|
308 |
if (so->so_state & SS_NOFDREF || so->s == -1) |
309 |
continue;
|
310 |
|
311 |
/*
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312 |
* Check for URG data
|
313 |
* This will soread as well, so no need to
|
314 |
* test for readfds below if this succeeds
|
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*/
|
316 |
if (FD_ISSET(so->s, xfds))
|
317 |
sorecvoob(so); |
318 |
/*
|
319 |
* Check sockets for reading
|
320 |
*/
|
321 |
else if (FD_ISSET(so->s, readfds)) { |
322 |
/*
|
323 |
* Check for incoming connections
|
324 |
*/
|
325 |
if (so->so_state & SS_FACCEPTCONN) {
|
326 |
tcp_connect(so); |
327 |
continue;
|
328 |
} /* else */
|
329 |
ret = soread(so); |
330 |
|
331 |
/* Output it if we read something */
|
332 |
if (ret > 0) |
333 |
tcp_output(sototcpcb(so)); |
334 |
} |
335 |
|
336 |
/*
|
337 |
* Check sockets for writing
|
338 |
*/
|
339 |
if (FD_ISSET(so->s, writefds)) {
|
340 |
/*
|
341 |
* Check for non-blocking, still-connecting sockets
|
342 |
*/
|
343 |
if (so->so_state & SS_ISFCONNECTING) {
|
344 |
/* Connected */
|
345 |
so->so_state &= ~SS_ISFCONNECTING; |
346 |
|
347 |
ret = write(so->s, &ret, 0);
|
348 |
if (ret < 0) { |
349 |
/* XXXXX Must fix, zero bytes is a NOP */
|
350 |
if (errno == EAGAIN || errno == EWOULDBLOCK ||
|
351 |
errno == EINPROGRESS || errno == ENOTCONN) |
352 |
continue;
|
353 |
|
354 |
/* else failed */
|
355 |
so->so_state = SS_NOFDREF; |
356 |
} |
357 |
/* else so->so_state &= ~SS_ISFCONNECTING; */
|
358 |
|
359 |
/*
|
360 |
* Continue tcp_input
|
361 |
*/
|
362 |
tcp_input((struct mbuf *)NULL, sizeof(struct ip), so); |
363 |
/* continue; */
|
364 |
} else
|
365 |
ret = sowrite(so); |
366 |
/*
|
367 |
* XXXXX If we wrote something (a lot), there
|
368 |
* could be a need for a window update.
|
369 |
* In the worst case, the remote will send
|
370 |
* a window probe to get things going again
|
371 |
*/
|
372 |
} |
373 |
|
374 |
/*
|
375 |
* Probe a still-connecting, non-blocking socket
|
376 |
* to check if it's still alive
|
377 |
*/
|
378 |
#ifdef PROBE_CONN
|
379 |
if (so->so_state & SS_ISFCONNECTING) {
|
380 |
ret = read(so->s, (char *)&ret, 0); |
381 |
|
382 |
if (ret < 0) { |
383 |
/* XXX */
|
384 |
if (errno == EAGAIN || errno == EWOULDBLOCK ||
|
385 |
errno == EINPROGRESS || errno == ENOTCONN) |
386 |
continue; /* Still connecting, continue */ |
387 |
|
388 |
/* else failed */
|
389 |
so->so_state = SS_NOFDREF; |
390 |
|
391 |
/* tcp_input will take care of it */
|
392 |
} else {
|
393 |
ret = write(so->s, &ret, 0);
|
394 |
if (ret < 0) { |
395 |
/* XXX */
|
396 |
if (errno == EAGAIN || errno == EWOULDBLOCK ||
|
397 |
errno == EINPROGRESS || errno == ENOTCONN) |
398 |
continue;
|
399 |
/* else failed */
|
400 |
so->so_state = SS_NOFDREF; |
401 |
} else
|
402 |
so->so_state &= ~SS_ISFCONNECTING; |
403 |
|
404 |
} |
405 |
tcp_input((struct mbuf *)NULL, sizeof(struct ip),so); |
406 |
} /* SS_ISFCONNECTING */
|
407 |
#endif
|
408 |
} |
409 |
|
410 |
/*
|
411 |
* Now UDP sockets.
|
412 |
* Incoming packets are sent straight away, they're not buffered.
|
413 |
* Incoming UDP data isn't buffered either.
|
414 |
*/
|
415 |
for (so = udb.so_next; so != &udb; so = so_next) {
|
416 |
so_next = so->so_next; |
417 |
|
418 |
if (so->s != -1 && FD_ISSET(so->s, readfds)) { |
419 |
sorecvfrom(so); |
420 |
} |
421 |
} |
422 |
} |
423 |
|
424 |
/*
|
425 |
* See if we can start outputting
|
426 |
*/
|
427 |
if (if_queued && link_up)
|
428 |
if_start(); |
429 |
} |
430 |
|
431 |
#define ETH_ALEN 6 |
432 |
#define ETH_HLEN 14 |
433 |
|
434 |
#define ETH_P_IP 0x0800 /* Internet Protocol packet */ |
435 |
#define ETH_P_ARP 0x0806 /* Address Resolution packet */ |
436 |
|
437 |
#define ARPOP_REQUEST 1 /* ARP request */ |
438 |
#define ARPOP_REPLY 2 /* ARP reply */ |
439 |
|
440 |
struct ethhdr
|
441 |
{ |
442 |
unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ |
443 |
unsigned char h_source[ETH_ALEN]; /* source ether addr */ |
444 |
unsigned short h_proto; /* packet type ID field */ |
445 |
}; |
446 |
|
447 |
struct arphdr
|
448 |
{ |
449 |
unsigned short ar_hrd; /* format of hardware address */ |
450 |
unsigned short ar_pro; /* format of protocol address */ |
451 |
unsigned char ar_hln; /* length of hardware address */ |
452 |
unsigned char ar_pln; /* length of protocol address */ |
453 |
unsigned short ar_op; /* ARP opcode (command) */ |
454 |
|
455 |
/*
|
456 |
* Ethernet looks like this : This bit is variable sized however...
|
457 |
*/
|
458 |
unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ |
459 |
unsigned char ar_sip[4]; /* sender IP address */ |
460 |
unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ |
461 |
unsigned char ar_tip[4]; /* target IP address */ |
462 |
}; |
463 |
|
464 |
void arp_input(const uint8_t *pkt, int pkt_len) |
465 |
{ |
466 |
struct ethhdr *eh = (struct ethhdr *)pkt; |
467 |
struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); |
468 |
uint8_t arp_reply[ETH_HLEN + sizeof(struct arphdr)]; |
469 |
struct ethhdr *reh = (struct ethhdr *)arp_reply; |
470 |
struct arphdr *rah = (struct arphdr *)(arp_reply + ETH_HLEN); |
471 |
int ar_op;
|
472 |
|
473 |
ar_op = ntohs(ah->ar_op); |
474 |
switch(ar_op) {
|
475 |
case ARPOP_REQUEST:
|
476 |
if (!memcmp(ah->ar_tip, &special_addr, 3) && |
477 |
(ah->ar_tip[3] == CTL_DNS || ah->ar_tip[3] == CTL_ALIAS)) { |
478 |
|
479 |
/* XXX: make an ARP request to have the client address */
|
480 |
memcpy(client_ethaddr, eh->h_source, ETH_ALEN); |
481 |
|
482 |
/* ARP request for alias/dns mac address */
|
483 |
memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); |
484 |
memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1);
|
485 |
reh->h_source[5] = ah->ar_tip[3]; |
486 |
reh->h_proto = htons(ETH_P_ARP); |
487 |
|
488 |
rah->ar_hrd = htons(1);
|
489 |
rah->ar_pro = htons(ETH_P_IP); |
490 |
rah->ar_hln = ETH_ALEN; |
491 |
rah->ar_pln = 4;
|
492 |
rah->ar_op = htons(ARPOP_REPLY); |
493 |
memcpy(rah->ar_sha, reh->h_source, ETH_ALEN); |
494 |
memcpy(rah->ar_sip, ah->ar_tip, 4);
|
495 |
memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN); |
496 |
memcpy(rah->ar_tip, ah->ar_sip, 4);
|
497 |
slirp_output(arp_reply, sizeof(arp_reply));
|
498 |
} |
499 |
break;
|
500 |
default:
|
501 |
break;
|
502 |
} |
503 |
} |
504 |
|
505 |
void slirp_input(const uint8_t *pkt, int pkt_len) |
506 |
{ |
507 |
struct mbuf *m;
|
508 |
int proto;
|
509 |
|
510 |
if (pkt_len < ETH_HLEN)
|
511 |
return;
|
512 |
|
513 |
proto = ntohs(*(uint16_t *)(pkt + 12));
|
514 |
switch(proto) {
|
515 |
case ETH_P_ARP:
|
516 |
arp_input(pkt, pkt_len); |
517 |
break;
|
518 |
case ETH_P_IP:
|
519 |
m = m_get(); |
520 |
if (!m)
|
521 |
return;
|
522 |
m->m_len = pkt_len; |
523 |
memcpy(m->m_data, pkt, pkt_len); |
524 |
|
525 |
m->m_data += ETH_HLEN; |
526 |
m->m_len -= ETH_HLEN; |
527 |
|
528 |
ip_input(m); |
529 |
break;
|
530 |
default:
|
531 |
break;
|
532 |
} |
533 |
} |
534 |
|
535 |
/* output the IP packet to the ethernet device */
|
536 |
void if_encap(const uint8_t *ip_data, int ip_data_len) |
537 |
{ |
538 |
uint8_t buf[1600];
|
539 |
struct ethhdr *eh = (struct ethhdr *)buf; |
540 |
|
541 |
if (ip_data_len + ETH_HLEN > sizeof(buf)) |
542 |
return;
|
543 |
|
544 |
memcpy(eh->h_dest, client_ethaddr, ETH_ALEN); |
545 |
memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 1);
|
546 |
eh->h_source[5] = CTL_ALIAS;
|
547 |
eh->h_proto = htons(ETH_P_IP); |
548 |
memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len); |
549 |
slirp_output(buf, ip_data_len + ETH_HLEN); |
550 |
} |